Glass-lined pump



Nov. 10, 1953 o. w. GREENE 2,658,454

GLASS-LINED PUMP Filed May 14, 1948 4 Sheet-Sheet 1 Uffo W (:FPPHQ Nov. 10, 1953 o. w. GREENE 2,658,454

GLASS-LINED PUMP Filed May 14, 1948 4 Sheets-Sheet 2 gwvom tm Uffo W (F ee 0 c Nov. 10, 1953 o. w. GREENE 2,658,454

GLASS-LINED PUMP Filed May 14, 1948 4 Sheets-Sheet l3 H1 127 H :l HHII HELIIHI. 1 3:; Il6

9;: '9 BiiiX H? Qttomwg Nov. 10, 1953 o. w. GREENE GLASS-LINED PUMP 4 Sheets-Sheet 4 Filed May 14, 1948 In wen/or Offo A/ 6/12/76 Patented Nov. 10, 1953 GLASS-LINED PUMP Otto W. Greene, Rochester, N. Y., assignor to The Pfaudler Company, a corporation of New York Application May 14, 1948, Serial No. 26,981

7 Claims.

My invention relates to pumps and more particularly to pumps of the centrifugal or rotating impeller type suitable for use in the pumping of chemicals. Reference is made to my co-pending application Serial Number 673,850, filed June 1, 1946, entitled Glass-Lined Pump now Patent No. 2,536,633, of which the present application is a continuation in part.

While the pump of my invention has primarily been developed for use in handling metal-attacking chemicals, the principles thereof may be employed in the pumping of other liquids as, for example, where the liquid being pumped is substantially chemically inert insofar as attacking metals, but of a viscous character and likely to solidify on the walls of the pump, or of such nature that it is subject to contamination requiring that the pump be frequently cleaned. Notwithstanding the fact that glass is substantially impervious to almost all acid chemicals, in-

sofar as I am aware, no one has successfully produced a commercially practical glass-lined pump. Many reasons probably exist for this. One of these exists in the problem encountered when glass is employed, of properly balancing and supporting the glass-coated rotor or impeller.

Another exists in the problem of preventing access of the liquid being pumped to the drive shaft and the stuffing box. Still another exists in the securing and maintaining of adequate clearance between the rotating impeller and the sidewalls of the enclosing casing, necessitated by reason of the frangible character of glass and distortion under the heat of fusing the glass. Other conditions, not heretofore adequately provided for, exist in the securing of adequate and positive lubrication, and in the proper support and mounting of the pump to enable quick and easy dismantling thereof for the purpose of draining and cleaning the casing.

An object of my invention is to provide an improved and commercially practical glass-lined pump, which may be built at reasonable cost, and in which all the parts exposed to the corrosive action of the liquid being pumped are coated with glass.

Another object of my invention is to provide a pump for use in conveying liquids under temperature or pressure or both wherein a fluid, preferably an inert gas, is introduced into the casing under pressure at such point that and the casing is arranged so that the liquid being pumped is separated, or walled off by the inert gas, and the liquid is thereby prevented from gaining access to the stuffing box and the drive shaft,

Another object of my invention is to provide a pump suitable for use in handling chemicals, wherein all the parts exposed to the liquid being pumped are coated with glass, and wherein means are provided for supporting and mounting the pump drive shaft and the pump impeller in a rigid plane of rotation, together with means for adjustably supporting the pump casing about the impeller so that the clearance between the casing and the rotating impeller unit may be adjusted Without disturbing the rotating impeller unit or its drive shaft from its fixed, rotatably supported position.

My invention further contemplates a vertically mounted glass-lined chemical pump wherein the lower half of the pump casing may be quickly and easily disconnected from the upper half for the purpose of enabling access to the pump casing and impeller for the purpose of cleaning and draining the casing.

Other objects and advantages of my invention will be set forth in the appended claims and will be clear from the following description, when taken in connection with the accompanying drawings, in which:

Fig. 1 is an external perspective view of the chemical pumping unit of my invention, and showing the vertical adjustable mounting thereof and the drive therefore;

Fig. 2 is a vertical view of the chemical pumping unit with half of the unit shown in section;

Fig. 3 is an enlarged sectional view of a portion of Fig. 2 showing, in detail, the means for sealing the casing and protecting the stuffing box;

Fig. 4 is a front elevation with parts cut away showing the means for supplying lubricant to the stuffing box, and means for supplying a fluid to i the pump casing under pressure for the purpose of protecting the stufiing box and drive shaft;

Fig. 5 is a sectional view through the impeller hub looking down upon the blades, illustrating how the impeller is balanced, and showing how 'the blades are made alternately wide and narrow;

ing with respect to the upper half, together with a self sealing gasket, the arrangement being particularly adapted for use when more severe chemical service is encountered; and

Fig. is a sectional view showing one of the adjustable supports for the casing.

The chemical pump of my invention (Fig. 2) comprises a main casing part II, a cover part [2 and an impeller or rotor I3. The impeller is connected to a drive shaft H1, in a manner presently described, which has mounted in driving relation at the upper end thereof (Fig. 1), as shown at 16, a multi-grooved pulley for the reception of V belts or any other suitable type of drive, indicated by the numeral H. The belts of the drive are arranged in driving relation with a grooved pulley [8 carried by a shaft (not shown), which is connected to a driving motor. The driving motor (not shown) is mounted on the rear of a support bracket I9,

One of the important features of my invention lies in the fact that the unit is mounted vertically to facilitate the cleaning and draining of the pump when the suction pipe 2| and the cover plate'l2 have been removed. This vertical arrangement is particularly important if the pump is employed for handling viscous liquids or other materials likely to solidify or agglomerate on the walls of the casing such as rubber latex, or if the pump is to be used to convey various chemicals. Thorough cleaning and draining of the unit is essential where the pump is used for handling a second chemical likely to be contaminated by any residue remaining in the casing from the first liquid pumped. The vertical mounting of the unit is also important for other reasons as will presently appear.

To facilitate the vertical mounting of the pump unit, the main part H of the pump casing is carried by a sup-port 22 which is preferably rigid with a main frame 23. The main frame is carried by side stands 24 with the pump suspended therebetween so that the unit is supported a suitable distance above the floor level to provide space to enable the cover plate [2 to be conveniently removed and dropped downward. The vertical suspension of the pump casing, in the manner above described, enables the independent adjustment of the pump casing with respect to the impeller for the purposes which will presently appear.

The drive shaft I4 extends vertically upward (Fig. 2) and has fixed thereto a shaft-wearing sleeve 26, the shifting of which upwardly along the shaft is limited by a shoulder ring 21 (Fig. 3) fitted to the shaft. The impeller has a hollow central hub 28, which has a bore 29 at its upper end in which a keyways 3| is cut. The impeller hub is connected to the drive shaft [4 by means of a Woodruff key 32 fitted to the keyway 3|, as shown most clearly in Fig. 3. The lower end of the drive shaft extends into a bore formed in the hub.

The lower end of the shaft sleeve 26 is provided with an annular recess 33 adapted to receive resilient packing 34 against which the annular end 36 of the hub of the impeller is adapted to seat so as to lock the packing in the recess. The drive shaft has a bore, as shown at 31, and extending internally and concentric with the shaft is an elongated stud 38 which is threaded into the casting forming the hub of the impeller, as shown at 39. The upper end of the stud projects through the shaft and is threaded to receive a nut 4|, the lower face of which engages the end of the drive shaft, as shown at 42. The upper end of the elongated stud is provided with a wrenchreceiving head 43 by means of which the elongated stud may be threaded into or out of the hub of the impeller in the manner shown at 39.

It will now be appreciated, upon threading the stud securely into the hub of the impeller and tightening down upon the nut 41 against the end of the drive shaft so as to apply a pull in pressure, that since the movement of the shaft-wearing sleeve 26 with respect to the shaft is limited, the entire impeller may be drawn upward along the drive shaft so that the end 36 of the hub will seal against the packing 34. It will, moreover, be apparent that the impeller is fixed in assembled relation with respect to the shaft and the shaftwearing sleeve, and that access of the liquid being pumped to the drive shaft is prevented by the seal formed between the end of the impeller hub and the lower end of the shaft sleeve. Moreover, access of the liquid being pumped to the hollow impeller hub is prevented.

The entire inner walls of the pump casing, as indicated at 44, are provided with a coating of glass or other vitrious materials which is impervious to almost all acid chemicals. Moreover, each of the impeller blades together with the hub of the impeller is similarly provided with a glass coating, as indicated at 46, so that all parts of the pump exposed to the liquid being pumped are protected against corrosive action by the chemicals being pumped (except as will later appear).

The processes for applying the glass coating to the casing and impeller, which may be of castiron or any other suitable metal, are well known. The cast casing and impeller give the unit the necessary mechanical strength to withstand the pressures and shocks encountered. The glass surfaces may be easily cleaned with water or, in case the chemicals pumped are not soluble in water and tend to adhere to the glass walls, suitable solvents other than water may be employed without injuring the glass coating.

As shown most clearly in Fig. 1, bolted to the main frame 23 is a bearing shell 66. The bearing shell extends in surrounding relation with the drive shaft and has mounted therein a plurality of ball bearing assemblies 61. The bearing is provided with a cap 68 and a nut 69 is threaded on the lower' end thereof. Since the bearing per se constitutes no part of my present invention, it will not further be described.

A stuifing box H extends in a concentric relation with the shaft sleeve 26, as shown most clearly in Figs. 2 and 3. The stufling box of a chemical pump is one of the greatest sources of pump failure due to attack by the chemicals on the packing and lubrication of the stuffing box. This difficulty I have overcome in a practical and novel manner as will hereinafter appear.

' Mounted in the stufling box is a bearing assembly comprising rings 13, which have conical bearing surfaces 14. A cylindrical bearing element 16 is provided with cooperating conical bearing surfaces. The bearing serves to support and steady the drive shaft, minimize the load on the packing, and acts as a lantern lubricator to distribute lubricant. On opposite sides of the bearing, the stuffing box is provided with rings of packing, which may be compressed by means of a packing gland, generally indicated by the numeral 11.

The packing gland comprises a plurality of semi-cylindrical elements 18 extending around the shaft sleeve and which are engaged by a cap 19. Adjustable screw assemblies 8| are threaded into the end of the stufiing box casting and apply, by means of springs, a yielding adjustable pressure on the stuffing gland and the packing.

The packing employed may be of any suitable type in accordance with the conditions encountered but preferably an asbestos packing is used because asbestos is chemically substantially inert and suitable for either high or low pressures. For the purpose of enabling distribution of lubricant to the packing the bearing elements 13 and it are suitably grooved (not shown) for the reception of the lubricant, which is supplied to the stuffing box in a manner presently described.

The main casing part I l is provided with an opening through which the drive shaft for the impeller extends and is provided with a flange 83 adapted to receive a cooperating flanged collar 86. The lower end of the stuihng box is provided with a flange 86 and a suitable gasket 87 is interposed between the flange 83 of the casing and the flange 86 of the stuffing box. The gasket is compressed to form a seal between the facing surfaces of the flanges and the stuffing box is held in rigid assembled relation with the pump casing by bolts, which extend through the flange St into the collar 84 (Fig. 1).

With the above described arrangement of stuffing box, upon removal of the bolts and loosening the packing gland, the entire stuffing assembly may be lifted upward so as to enable access to the stufiing box for removing hardened or worn packing and inspection of the shaft sleeve. By the use of a suitable gauge, the stuffing box may be reassembled with respect to the casing in concentric relation with the shaft sleeve. It will be particularly noted that the position of the drive shaft is fixed when the elongated stud is pulled in; that the stuffing box is independently adjustable with respect to the drive shaft; and that the stuffing box is supported entirely by the pump casing.

Another of the problems encountered in the manufacture of a glass-lined pump arises in connection with the impeller blades and the assuring of clearance between the blades and the pump casing without undue loss in efficiency. This problem arises due to warpage and distortion unavoidably encountered during the application of the vitreous coating to the impeller. Only three impeller blades can be held in one rotational plane when distortion or warpage during the application of the glass coating has occurred.

In the drawings I have shown an impeller having six blades and I prefer, for reasons of eflieiency, this number of blades. As will clearly appear from an examination of the blade sections of Fig. 5, the alternate blades are wide and I narrow; the three wide blades being those which can be brought true to a rotational plane in the final machining of the internal bore of the impeller. Briefly the method employed of making the impeller comprises first rough grinding the casting. The impeller is then assembled with respect to a special conical wood faced face plate which engages the three wide blades. After centering in the lathe the casting is turned and later ground and brought to balance. The casting is then glass coated and during this operation some distortion is impossible to avoid. However, the impeller is reassembled with respect to the wood face plate with the three wide blades in contact therewith. The hub of the impeller is then bored with the axis of the bore normal to the rotational plane of the blades. By making the intermediate blades narrower, an allowance is made for some distortion of these intermediate blades. With distortion of the intermediate blades allowed for, clearance between the blades of the impeller and the casing walls can be secured in final assembly.

In addition to the problem of providing impeller blades, which will rotate in a true path of travel, the use of a glass coating on the casing walls and the impeller blades makes it impossible to employ conventional methods of providing for clearance between the casing walls and the rotating blades. This is frequently accomplished in conventional pumps by grinding the casing wall or impeller. Adequate clearance is extremely important for the reason that if the agitator blades should strike the casing sidewalls, chipping and breaking of the glass will occur exposing the metal, which will result in early failure in service. Because of this necessity of insuring adequate clearance, I have provided novel means for adjusting the pump casing with respect to the impeller. This enables the impeller and its drive shaft to be rigidly located and pulled in, as described above, and the adjustment of clearance to be accomplished without disturbing the impeller or drive shaft.

As shown in the drawings (Figs. 1 and 10), the main casing part I l is provided with three upwardly projecting bosses 9|, each of which has a threaded bore 92. A stud 93 is threaded into each of the bores and extends through a threaded bore formed in the support plate 22. A nut 94 is threaded on the upper end of each of the studs 93, and engages a jack-screw S6. The jack-screw 9B is provided with external threads 9'! which 00- operate with the threaded bore of the support plate 22. A pair of lock nuts 99 are threaded on the jack-screw, one on each side of the support plate 22. A wrench-receiving element is pr0- vided on the j ack-screw by which the jack-screw may be turned to thread the jack-screw into and out of the support plate.

When it is found, upon examination in a man ner which will presently be made clear, that the clearance between the main casing part and the impeller blades is insufficient or too great, the main casing part may be raised or lowered, as required, by loosening the nut 94 and the lock nuts 89. After the clearance has been properly adjusted, the nuts are tightened against the support plate and the main casing part is then properly positioned and rigidly supported with respect to the impeller. If it is determined upon examination that the casing is cocked with respect to the impeller, one or more of the jack-screws may be adjusted until the clearance over the blades is uniform.

I have provided novel means for testing or determining the clearance between the impeller blades and the casing. Such means may comprise a loop or wire of a diameter in accordance with the desired clearance. For example, if it is desired that a one-sixteenth clearance be provided, a one-sixteenth inch diameter wire would be used. The clearance wire has its ends fas tened in a handle Mil. To test the clearance, the clearance wire or gauge is inserted in the suction opening, as indicated in Fig. 2, and passed between the lower edges of the blades and the cover plate l2, and also looped over the ends of the blades and passed between the upper edges of the blades and the main casing part I i. As previously mentioned, three of the blades are adjusted in the final boring operation so that they revolve in a true rotational plane. Moreover, the parts of the casing adjacent the blades are accurately machined prior to fusing the glass and the method employed minimizes the effects of distortion at the surfaces adjacent which the blades run. With the three wide blades rotating in a true plane and with the adjacent surfaces of the casing heldtrue, substantially uniform clearance can be obtained over the blades by accurately adjusting the casing with respect to the impeller as previously described.

The blade clearance should be tested, rotating the impeller by hand, each time any adjustment of the pump is made and before the pump is started, as it is essential that the glass surfaces of the blades or casing be not abraded or broken so as to permit access of the chemicals being pumped to the metal of the casing or blades. It will thus be apparent that I have provided novel means for not only adjusting the casing, with respect to the rotating impeller, but also have provided novel means for testing the clearance and insuring that, in operating, the blades will not engage or strike against the casing sidewalls.

One of the problems encountered in making a glass-coated pump impeller is that of securing accurate balance of the impeller. The usual method with metal impellers is to grind or file the impeller and the blades thereof until accurate balance is obtained. This method of balancing is impossible with a glass-coated impeller, nor is it possible to balance the impeller prior to the application of the glass coating with any assurance that, after the coating has been applied, the impeller will remain in balance. Not only is some distortion impossible to avoid but also the glass coating cannot be applied to a uniform thickness. In the pump of my invention, the balancing of the impeller is accomplished in a novel manner.

During the preliminary machining prior to the application of the glass coating the impeller is brought into approximate balance. Within the impeller hub, as shown most clearly in Fig. 5, I have provided a series of ribs I08, which extend preferably radially of the hub along the general lines of the blades. The ribs terminate short of the inner sidewalls I09 of the hub so as to provide a recess between the end of each rib and the inner sidewall of the hub.

One or more impeller balancing elements may then be positioned between the ends of the ribs and the inner sidewalls of the hub. In Fig. I have shown one of the impeller balancing elements II I in position. These balancing elements preferably comprise a rubber center of somewhat cylindrical shape, which is provided with an exterior lead sleeve. The impeller balancing elements may be then calked in position and will be distorted in the calking so as to shape themselves, as shown in Fig. 5, in accordance with the space available and be locked between the ends of the ribs and the inner sidewalls of the hub. It will be appreciated that any number of balancing elements or calks may be employed and that they may be of various weights so that by properly positioning them accurate balancing of the impeller may be attained. It will be particularly noted that centrifugal force does not tend to loosen the calks and that no bolts or screws are required to fasten the calks.

Another of the problems encountered in any chemical pump, as previously mentioned, i the protection of the stufiing box and the packing and the pump shaft from contact with the chemicals being pumped. In the pump of my invention I have provided novel means for preventing 8 the chemicals being pumped from gaining access to the stufiing box and shaft. In accordance with this phase of the invention, such means are part of, or operate in cooperation with, the stufllng box lubrication system.

The system is provided with a preferably cylindrical lubricator II6, shown most clearly in Fig. 4, having a reservoir III for the reception of the lubricant. Preferably the lubricant employed is a good grade of mineral oil. The lubricator is provided with a window II8, through which a tube II9 extending into the lubricator i visible. The tube extends upward and projects from the lubricator through a fitting HI and is connected by a fitting I22 to a tube I23. The tube or line I23 is provided with a globe or shut-oif valve I24 and a needle valve I26.

The line I23 is connected to a source of gas under pressure. Preferably an inert gas is employed, which will not corrode the metal parts with which it contact nor have a deleterious effect on the lubricant. The source of gas is maintained at a higher pressure than will normally be required in the system; the exact amount of gas to balance the system required for the particular conditions encountered being regulated by the needle valve I26.

When the system is in operation, the inert gas is supplied through the tube H9 and bubbles upward through the lubricant, as indicated in Fig. l. This gives a visible indication that the system is in operation. The gas passes upward to the top of the lubricator through a connection I 27 surrounding the tube H8 into the fitting I2I The fitting I2I is connected by a line I 28, and fittings I29 to a glass-walled tube or sight glass I3I. The sight glass I3I is suitably sealed and supported in position by means of end plates I32 and tie rods I33 connecting the end plates.

The casing is provided with an opening I34 adapted to receive, in fluid tight arrangement, a fitting I36, which is connected to the sight glass as shown. By this arrangement, the inert or scavenging gas is supplied to the impeller casing under pressure and this pressure may be regulated by the needle valve I26. Lubricant is supplied to the reservoir II'I through a fitting I4I, which may have a valve I42 therein, and any desired lubricant coupling I43 adapted to receive a lubrication pump may be employed. Lubricant, under the pressure of the gas supplied to the reservoir II'I, flows through a line I44 to a valve controlled fitting I46 (Fig. 2). The fitting I46 is connected through a bore I50 in the stufling bgxTgvall to a recess I55 formed in the bearing It will be particularly noted that the opening I34 into the pump casing is remote from the ends of the blades of the impeller and is as close as possible to the hub thereof. The annular cone shaped space around the hub of the impeller is filled, during operation of the pump, with the scavenging gas supplied thereto, which is at a pressure sufiicient to balance the liquid being pumped at the pressure thereof existent adjacent sa1d cone shaped space. The pressure developed by a centrifugal pump increases in accordance with the square of the distance from the axis of the impeller. Thus, the gas pressure adjacent the annular space around the hub is considerably less than the pressure developed by the pump in the volute space I56 surrounding the impeller. For example, if the pressure developed by the pump is fifty pounds, it may be necessary to supply scavenging gas under a pressure of only ten pounds in order to balance or wall off the fluid pumped and prevent it from gaining access to the stuffing box.

It will be particularly noted that the hub of the impeller is closely spaced with respect to the wall of the main part of the casing II along the line I I-6. This close spacing of the parts forms an annular dam, which assists in preventing the liquid being pumped from entering the space above the dam. Preferably the scavenging gas pressure is regulated so that the dam approximately marks the line of separation between the scavenging gas and the liquid.

The action of the system on the fluid pumped and the scavenging gas is similar in some respects to that produced by a centrifuge. That is, the liquid pumped, being heavier than the gas, is thrown outward by the impeller. The lighter gas tends to float on the liquid nearer the center of rotation. Moreover, it will be noted that the space into which the gas flows is above the liquid, and thus gravity assists in the action. The entire space surrounding the hub of the impeller is iilled with the scavenging gas, forming a wall of inert gas, which prevents the liquid being pumped from gaining access to the stufiing box. Under certain conditions of operation, the fluid in the space above the dam may be a frothy mix ture of gas and liquid. However, the fluid adjacent the stuffing box is primarily or wholly a gas, because of the tendency of the lighter gas to rise and the centrifuge effect of the rotating impeller.

Lubricant flows to the stufiing box through the line I44 and through the lubricant grooves provided in the bearing I3, I6. This lubricant is under a pressure slightly greater than that of the scavenging gas by reason of the fact that there is a head of liquid on the stuffing box determined by the height of the surface of the liquid in the lubricator II6 above the stufling box. This excess pressure is suflicient to insure that whatever leakage occurs is a leakage of lubricant through the stufling box into the pump. However, preferably the static head or pressure by which the pressure of lubricant exceeds that of the scavenging gas in the casing, is just approximately the amount of pressure required to overcome the resistance to the flow of lubricant and to force lubricant through the bearing lubrication grooves and through the packing. When properly arranged, the pressure of lubricant at the bottom of the stuffing box approximately balances the gas pressure within the pump casing so that no appreciable leakage or flow occurs in either direction.

In practice with the pump developing the desired pressure, the needle valve I26 is set so that no liquid is visible in the sight glass I3I. If liquid is visible in the sight glass, it is an indication that the gas is not reaching the casing because it is not at a pressure high enough to counterbalance the pump pressure. Upon opening the needle valve I26, the pressure of gas and also the pressure of lubricant will be increased so that the scavenging gas will force the fluid being pumped out of the sight glass I3! and occupy the space in the casing surrounding the hub of the impeller.

In a chemical pump, it is essential that the pump be capable of being thoroughly and quickly cleaned particularly when the liquid is pumped at an elevated temperature and tends to solidify when cold. With the pump of my invention after the suction pipe 2-I has been removed, the lower half or cover of the casing may be quickly disconnected from the upper half and dropped downward to permit draining and cleaning of the casing. The suction pipe 2| is coupled to the suction of the pump by means of a pair of flanged rings I5! (Fig. 2) and I52 Fig. l), which are bolted together. vThe annular end of the suction of the pump is flanged, as shown at I53, to receive coupling element I5| and the end of the suction pipe is similarly flanged (not shown) so as to receive the coupling element I52. Packing I54 is inserted between the flange of the suction pipe and the flange of the pump suc= tion, which is compressed to form a seal when the coupling halves I5I and I52 are bolted together. The volute the, wherein the kinetic energy imparted by the impeller is converted to pressure, is connected to a discharge pipe I (Fig. 1).

The quick locking and releasing means or breach lock for the two halves of the casing comprises an annular cylindrical ring I58 (Fig. 1), which extends around the periphery of the two halves of the casing. The ring has a lip I (Fig, 1), which extends around the ring, and engages an annular machined surface formed on the main part II of the casing. The ring is provided with a cut-out I59 into which project the teeth of a rack Ifil. The rack is cut on the arc of a circle and is bolted, as indicated at I62, to the upper half or main part II of the casing. The annular ring I53 is provided with a boss I63, which has a bore r64 (Fig. 6). A pinion I66 has its lower end journaled in the bore and the teeth thereof mesh with the teeth of the rack, as shown in Fig. 6. The lower end of the pinion has a groove or notch I53 cut therein, in which is seated the end of a set screw I69 for holding the pinion in its seat.

The lower periphery of the annular ring I58 has inwardly turned teeth I'II, which extend entirely around the inner circumference thereof. The lower face of the casing is provided with an annular flat surface I12 adapted to receive an annular ring I13, shown most clearly in Figs. 7 and 8. The annular ring I13 is bolted to the annular face I12. The outer circumference of the annular ring I13 is provided with a plurality of cut-out notches I14, which correspond in number and location to the teeth I1I of the annular ring I58. Interposed between each of the cut-outs I14 is a projection I16, which has an inclined cam surface adapted to cooperate with the teeth IT! to lock the halves of the easing together, and apply pressure between them.

An annular ring of packing I11 lies in annular pocket formed between the casing halves so that when pressure is applied between the halves of the casing the packing is compressed and spread into this groove so as to securely seal the parts.

It will now be appreciated that when the parts are assembled, as shown in Fig. 6, that by applying a wrench to the wrench-receiving part I8I of the pinion I66, the pinion will turn on the rack so as to rotate the annular ring I58 about the casing. This rotation shifts the teeth III with respect to the projections I16 so that the teeth register with the cut-outs I14 ofthe an nular ring I13. When the teeth I1I are in registry with the cut-outs I14 the lower half of the casing, together with the annular ring I13, is free to be dropped downward.

When disassembling the casing, blocks should be positioned below the lower half of the casing for receivingthe casing and preventing a jar 1 likely to damage the glass inner wall. Upon removal of the cover or lower half of thecasing. the casing may be drained and. cleaned. If desired, when cleaning the casing, the pump impeller may be removed by loosening the nut ll and unthreading the pull rod by applying a special tool to the head 4-3. Because of the quick and easy operation of the breach lock, the casing may be frequently and thoroughly cleaned without undue interruption of operations, which is essential, for example, if the pump is to be used for pumping difierent chemicals or if viscous liquids are handled.

After the pump has been cleaned, it may be quickly reassembled by the reverse of the operations, above described. When the teeth I'II engage the cam surfaces of the annular ring I13, continued rotation of the annular ring I58 appliespressure on the casing parts and on the packing. I" to seal the annular joint between the two halves of the casing.

The above described breach lock is suitable for use when the pump is to be used for moderate chemical service. However, when severe chemical service is encountered I have found the easing lock, shown in Fig. 9, more satisfactory. The arrangement shown in Fig. 6 conceals any leakage which may develop and for this reason is not preferred when corrosive chemicals are being pumped. In arrangement of Fig. 9 each half of the casing is provided with an annular lip I81, which has a rounded cam surface. A plurality of locking elements, generally indicated by the numeral I88, are spaced around the periphery of the two halves of the casing. These locking elements I88 comprise a bolt I89 having a, head I9I. A pair of clamps I 92 are mounted on each of the bolts, each clamp having a down turned cam surface I 93,- A nut I94 is threaded on the end of each of the bolts and by drawing up on the nuts I94, the cam surfaces on the casing and the cam surfaces on the clamps are caused to cooperate to applypressure between the halves of the casing.

When highly corrosive chemicals are encountered, making' it desirable to use this type ofeasing look, I have found two rings of packing I88, I91 more satisfactory. The packing I96 is of a material that is resistant to the particular chemical being pumped and may be somewhat porous. The packing I91 forms the seal to prevent leakage of the corrosive liquid which would be likely to corrode the locking elements I 88. For the purpose of receiving the packing I96 each half of the casing is provided-with a substantially fiat surface I98 and an annular groove I99 for thereception of the packing I91. It will be particularly noted that the pressure developed by the pump tends to wedge the packing in position and increase the effectiveness of the seal.

While the casing lock, shown in Fig. 10, is less satisfactory than the breach lock above described from the standpoint of not being capable of. as rapid application and removal, it may be employed for maintaining as seal between the halves of the casing under extremely severe chemical conditions. It will be particularly noted that with both sealing arrangements, pressure is applied on the packing so asto squeeze the packing and seal the annular parting'between the two halves of the casing. In both arrangements shown for lo :kingv and sealing the two halves of the. casing, the locking elements are applied externally' of the casing. They are thusremoved from con- I2 tact with the chemicals being. pumped and hence the possibility of corrosion thereof is minimized.

While I have shown and described the preferred form of my invention, it will be appreciated that various changes and modifications may be made, particularly in the form and relation of parts, without. departing from the spirit of my invention as set. forth in the appended calims.

I claim:

1. A pump of the character described comprising, in combination, a casing including a. main casing part and cover part having a suction opening, an impeller having blades and a hub, a drive shaft extending into said hub, means including a stud: extending through said drive shaft and fixed to the hub internally thereof for fixing said impeller with respect to said drive shaft, means includinga plurality of adjustable supports for adjusting the main part of the casing with respect to said blades to provide a uniform clearance between the casing and the plane of rotation of the blades, and means for fixing the cover part with respect to the main casing part.

2. A pump of the character described comprising, in combination, a casing including a main casing part and a cover part having a suction opening, an impeller having blades and hub, a drive shaft extending into said hub and slidably keyed with respect thereto, a sleeve fixed to said drive shaft, a rod extending through said drive shaft and fixed to the hub of the impeller, a sealing element between the end of the hub and said sleeve, means for pulling on said rod to draw said impeller along said shaft and thereby compress said sealing element between the end of the hub and said sleeve, and means for adjusting said. main casing part with respect to the plane of rotation of the blades-so as to provide clearance around the blades, after the impeller has been fixed in position.

3; A pump of the character described. com-.- prising,, in. combination, a casing including a maincasing part and a cover part having a suction. opening,.an impeller having blades and a hub,- a driveshaft extending into said hub and slidably keyed with respect thereto, a sleeve fixed'to said drive shaft, a rod extending through said. drive shaft: and fixed to the hub of the impeller, a sealing element between the end of the hub and said sleeve, means for pulling on said rod to draw said impeller along said shaft and thereby compress said-sealing element between the end of the hub-and said sleeve, and means including a plurality-of adjustable elements for supporting and forz adjusting said main casing part and said cover part with respect to-the plane of rotation of the blades so as to provide clearance around: the blades has been fixed in position.

4. A pump of the character described comprising, in combination, a casing including a main casing partand a cover part having a suctionopening, an impeller. having blades and a: hub, a drive shaft extending into said hub and slidablykeyed withrespect thereto, a sleeve fixed to said drive. shaft, a rod extending through said drive shaft and fixed to the hub of the impeller, asealing element between the end of the hub and said sleeve, means for pulling on said rod to drawsaid impeller along said shaft and thereby compress said sealing element between the end of the hub and said sleeve, a stuffing box extendingconcentrie with the shaft, means including a sealing element for drawing the stufll-ng box into sealing. relation with the. main casing after the impeller part, and means for adjusting said main casing part and said cover part with respect to the plane of rotation of the blades so as to provide clearance around the blades after the impeller has been fixed in position.

'5. A pump of the character described comprising, in combination, a casing including a main casing part and a cover part having a suction opening, an impeller having blades and a hub, a drive shaft extending into said hub, means including a stud extending through said drive shaft and fixed to the hub internally thereof for fixing said impeller with respect to said drive shaft, a fixed part, means including a plurality of adjustable supports depending from said fixed part for adjusting the main part of the casing angularly with respect to the plane of rotation of said blades to provide a uniform clearance between the casing and the plane of rotation of the blades, and means for fixing the cover part with respect to the main casing part.

6. A pump of the character described com-- prising, in combination, a casing including a main casing part and a cover part having a suction opening, an impeller having blades and a hub, a drive shaft extending into said hub and slidably keyed with respect thereto, a sleeve fixed to said drive shaft, a rod extending through said drive shaft and fixed to the hub of the impeller, a sealing element between the end of the hub and said sleeve, means for pulling on said rod to draw said impeller along said shaft and thereby compress said sealing element between the end of the hub and said sleeve, and means for adjusting said main casing part angularly with respect to the plane of rotation of the blades so as to provide a clearance around the blades after the impeller has been fixed in position and said sealing element has been compressed in sealing relation to its associated parts.

7. A pump of the character described comprising, in combination, a casing including a main casing part and a cover part having a suction opening, an impeller having blades and a hub, a drive shaft extending into said hub and slidably keyed with respect thereto, a sleeve fixed to said drive shaft, a rod extending through said drive shaft and fixed to the hub of the impeller, a sealing element between the end of the hub and said sleeve, means for pulling on said rod to draw said impeller along said shaft and thereby compress said sealing element between the end of the hub and said sleeve, a fixed part, and

OTTO W. GREENE.

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